Aiming at the big difference in the three-axis size of broad bean seeds, which leads to the difficulty of seed clearing and easy reseeding, a precision seed metering device for broad bean was designed with a chain spoon flip-over clearing type. The structural parameters of the key components were determined through theoretical calculations, and the dynamic model of the seed cleaning process was established. The factors that affected the seeding performance indicators were obtained as follows: spring tension, seed layer height, operating speed, seed cleaning area, inclination of the chain and the inclination of the chain in the filling zone. The DEM-MBD coupling method was used to further determine the influencing factors, and the spring stiffness coefficient was checked, and the spring tension was determined to be 50N and the seed layer height to be 75mm. Taking the inclination angle of the seeding chain in the filling area, the inclination angle of the seeding chain in the cleaning area and the operating speed as the test factors, the qualified index, the replay index, and the missed seeding index as the test indicators, and the quadratic regression orthogonal rotation combined test method was used for the bench test. The test results showed that the optimal parameter combination was the operating speed of 4.25km/h, the inclination of the seeding chain in the clearing zone was -2.9°, and the inclination of the seeding chain in the filling zone was 74°. It was obtained that the qualified index was 93.83%, the replay index was 5.67%, and the missed seeding index was 0.50%, which met the requirements of broad bean seeding.